Definitions for "Atria"
The upper chambers of the mammalian heart that receive blood returning from the venous circulation (right atrium) or from the lungs (left atrium).
paired upper heart chambers responsible for receiving blood returning to the heart from the body
plural of atrium. Blood is returned from the lungs, to the left atrium, from where it is pumped into the left ventricle and then round the body, or from the body, to the left atrium be pumped into the right ventricle and then to the lungs